Meyer WOODCHUCK 526 User manual

INSTRUCTION AND PARTS BOOK
FOR
MODELS 526, 2900, & 4000
WOOD/COAL FURNACES
08/2012
Installation must be made in accordance with local and state codes which
may differ from manual. Save these instructions.
Manufactured by
Meyer Mfg. Corp.
Phone [phone]
Fax [phone]
Dorchester, Wisconsin 54425
The Undefeated Heavyweight Champion!

2
TRANSPORTATION DAMAGES
Before reading this manual and proceeding with the installation, inspect your new Woodchuck to make sure there
were no shipping damages. If you find there have been damages incurred, call your dealer immediately. He will
then take a course of action to correct the problem.
We are constantly improving and updating our product in order to provide the
highest quality and value possible. Consequently pictures might sometimes differ
slightly from the actual product.
INTRODUCTION
Dear Woodchuck Owner,
Congratulations on your purchase of a Woodchuck heating appliance. Un-
doubtedly you have given much consideration to your purchase and we’re
proud that you have selected a Woodchuck. Pride in craftsmanship and engi-
neering have made your Woodchuck the finest heating appliance available to-
day.
Solid fuels are abundant and inexpensive. Wood is our only renewable
source of fuel and conservative estimates put our coal reserves at 800 years.
Our dual fuel units provide the savings and comfort of solid fuels and the con-
venience of electric heat in one attractive package.
There is no substitute for quality. That is why thousands of people like you
have purchased a Woodchuck. They also felt it was the best equipment to
serve their heating needs, now and in years to come. We ask that you follow
our policy of “safety first” and we strongly suggest that you read through the
owner’s manual before installing and operating your furnace.
For a lifetime of satisfaction, thank you for not compromising quality.
Sincerely,
Donald A. Meyer
President
MEYER MANUFACTURING CORP.

3
Introduction .....................................................2
Furnace Safety ...................................................4
Specifications ....................................................5
General Information .................................................6
High Quality Construction ...........................................6
Efficiency ....................................................6
Comfort .....................................................6
Additional Comfort and Saving .........................................7
Operation ......................................................8
Common Sense.................................................8
! If You Have a Chimney Fire ! .........................................8
! Important ! Operation Procedure in the Event of Power Failure .......................8
Operating Your Woodchuck Furnace ......................................9
Startup .....................................................9
Electrical Switches ...............................................9
Burning Wood in Your Woodchuck .......................................10
Helpful Hints ..................................................10
Ash Removal .................................................10
Burning Coal in Your Woodchuck........................................11
Starting a Coal Fire ..............................................11
Recharging ..................................................11
Banking ....................................................11
Bituminous Recharging ............................................11
Helpful Hints ..................................................12
Ash Removal .................................................12
Maintenance ....................................................13
Trouble Shooting .................................................14
General Requirements .............................................16
Placement and Minimum Clearances......................................16
Installation .....................................................16
Chimney Installation...............................................18
Installing Your Woodchuck ...........................................19
Stove Pipe Installation .............................................19
Installation of a Barometric Draft ........................................19
Air Duct Installation ...............................................20
Woodchuck Final Assembly...........................................21
Optional Shaker Grate Installation for Model 526...............................21
Install Shaker Grate Handle, Model 2900 Only ................................22
Install Firebrick ................................................23
Install Optional Catalytic Combustor (Model 2900/4000) ...........................24
Assemble Manual Draft-Model 526 Only ...................................24
Install Comfort Control Center and Forced Draft Blower ...........................24
Install Circulating Blower ...........................................25
Install Filter Box ................................................25
Electrical Hookup ...............................................26
Repair Parts ....................................................28
Personal Data Information for Future Reference ................................34
How to Read Your Serial Number .......................................34
Limited Warranty ................................................35
TABLE OF CONTENTS

4
FURNACE SAFETY
THERE ARE INHERENT HAZARDS ASSOCIATED WITH THE OPERATION OF WOOD/COAL FURNACES. FOR
YOUR SAFETY READ, UNDERSTAND, AND HEED THE FOLLOWING:
DANGER:
RISK OF FIRE OR EXPLOSION. DO NOT BURN GARBAGE, GASOLINE, DRAIN OIL, OR OTHER FLAMMABLE
LIQUIDS. FAILURE TO HEED MAY RESULT IN SERIOUS PERSONAL INJURY OR DEATH.
DANGER:
NEVER USE CHEMICALS OR FLUIDS SUCH AS GASOLINE, CHARCOAL LIGHTER FLUID, DRAIN OIL, FUEL
OIL OR KEROSENE TO LIGHT A FIRE IN YOUR WOODCHUCK. FAILURE TO HEED MAY RESULT IN SERIOUS
PERSONAL INJURY OR DEATH.
DANGER:
DURING OPERATION, LOADING AND ASH DOORS, AND EXPOSED FIREBOX ARE EXTREMELY HOT. NEVER
TOUCH THESE PARTS WHEN HOT. FAILURE TO HEED MAY RESULT IN SERIOUS PERSONAL INJURY.
CAUTION:
· Risk Of Fire
· Do Not Operate With Fuel Loading Or Ash Removal Doors Open.
· Do Not Store Fuel Or Other Combustible Material Within Marked Installation Clearances.
· Under Certain Conditions Of Use, Creosote Buildup May Occur Rapidly. Inspect And Clean Flues And Chimney
Regularly.
· Wait 10 Seconds On First Latch Before Refueling. Opening Loading Door Rapidly Can Cause A Flame To Flash
Out The Door. Use Caution When Opening Loading Door.
· Unsafe To Load Coal Above Top Of Brick.
· Keep Ash Pan Out Of Unit During Operation. Ash Pan Can Get Very Hot.
· Ash Can Must Be Placed On A Noncombustible Surface.
· Never Use Anything But An Air Tight Metal Container To Dump Your Ashes In. Every Year Many Fires Are
Caused By Emptying Ashes Into Cardboard Bo es Or Paper Bags.
·
Proven Fact - Small Red Embers Buried In Ash Cans Stay Red Hot For Days. Ashes Are A Good Thermal Insu-
lator And Keep Enough O ygen Away So Embers Do Not Burn Out.
THERE ARE ADDITIONAL HAZARDS ASSOCIATED WITH IMPROPER INSTALLATION OF WOOD/COAL FUR-
NACES AND WITH SERVICE AND MAINTENANCE OF WOOD/COAL FURNACES. FOR YOUR SAFETY READ,
UNDERSTAND, AND HEED THE FOLLOWING:
WARNING:
DISCONNECT APPLIANCE FROM ELECTRICAL SUPPLY BEFORE SERVICING UNIT. FAILURE TO HEED MAY
RESULT IN SERIOUS PERSONAL INJURY OR DEATH.
CAUTION:
·
Equipment Must Be Installed By A Qualified Heating Person.
·
Only class A All-fuel Or Solid Fuel Chimneys Intended For Use With Your Woodchuck Should Be Used.
·
Furnace Must Be Installed On A Noncombustible Floor Or 3/8" Thick Fireproof Millboard Or Equivalent.
FAILURE TO HEED MA RESULT IN SERIOUS PERSONAL INJUR OR DEATH.

5
DISCLAIMER NOTICE
The heating capacity specifications are provided as guidelines only and in no way guarantee the output or capacity
of the units. The actual BTU output depends on the type of fuel being burned and its condition, the thermostat set-
ting, the draft adjustments and the chimney that the unit is installed into.
Height 42.5"
Width 24"
Depth 26"
Blower 850 to 1850 CFM
Ma . BTU Capacity 120,000
Log Size 22"
Loading Door Size 14" 12"
Weight, Appro . 445 lbs.
Warm Air Plenum 20" 23"
Flue Outlet 6" Dia.
Flue Collar Height 41" Overall Height
Secondary Heat E change YES
Listings UL391, CSA B366,
1-M ETLM
Firebo Chamber 6.10 cu. ft.
MODEL 526
SPECIFICATIONS
Height 48.5"
Width 26"
Depth 28"
Blower 850 to 1850 CFM
Ma . BTU Capacity 150,000
Log Size 22"
Loading Door Size 15" 13"
Weight, Appro . 700 lbs.
Warm Air Plenum 20" 23"
Flue Outlet 8" Dia.
Flue Collar Height 47" Overall Height
Secondary Heat E change YES
Listings UL391, CSA B366,
1-M ETLM
Firebo Chamber 7.70 cu. ft.
MODEL 2900
Height 51.5"
Width 26"
Depth 33"
Blower 850 to 1850 CFM
Ma . BTU Capacity 180,000
Log Size 24"
Loading Door Size 15" 13"
Weight, Appro . 815 lbs.
Warm Air Plenum 20" 23"
Flue Outlet 8" Dia.
Flue Collar Height 50" Overall Height
Secondary Heat E change YES
Listings UL391, CSA B366,
1-M ETLM
Firebo Chamber 9.10 cu. ft.
MODEL 4000

6
GENERAL INFORMATION
Woodchuck furnaces represent the ultimate in solid fuel
and dual fuel heating appliances. From the massive
model 4000 to the economy model 526, each unit is de-
signed to be attractive, durable and efficient while pro-
viding the safety and comfort you and your family
deserve.
HIGH QUALIT CONSTRUCTION
Constructed of high grade, heavy gauge, hot rolled
steel plate, the firebo is continuously welded for an air-
tight seal and structural strength. The heavy duty cast
iron doors are equipped with a positive latching device
for your safety. The loading door has a two-step safety
latch. The large cast iron grates provide for durability
and help promote efficient combustion of the fuel. The
firebo is lined with heavy duty firebrick and is done so
without any retainers to warp or burn out. These fea-
tures together with high quality electrical components
provide the safety, efficiency and total control possible
only in a Woodchuck. Total control means that you can
better avoid overheating the unit and developing e ces-
sive and unsafe temperatures.
Woodchuck furnaces are subjected to the most strin-
gent test criteria applicable by an independent third
party testing laboratory and listed/labeled as having
met or e ceeded those standards. Finally, any ma-
chine, even this Woodchuck, is only as safe as the per-
son operating it. This is why we have compiled this
comprehensive manual to assist you in operating your
Woodchuck properly and safely. Please read and follow
all instructions.
EFFICIENC
The total efficiency of a unit is broken down into com-
bustion efficiency and transfer efficiency. We know that
when woodburning, 20% of it burns as fi ed carbon.
The other 80% is in the gaseous state as it burns.
Therefore, to obtain efficient combustion of the wood it
is necessary to introduce 20% of the o ygen under
the fire to promote combustion of the solid material and
80% over the fire where it can readily react with the
gaseous material. Coal burns just the opposite of wood.
80% of it burns as fi ed carbon and 20% burns in the
gaseous state. Therefore, before a furnace can burn
coal or wood efficiently, it must provide the 80/20 ratio
of combustion air and allow the operator to reverse the
ratio depending on the fuel being used. Combustion air
must be warm when it enters the firebo to further pro-
mote complete combustion. Your Woodchuck furnace
provides all these features and more. Here is how:
when combustion air enters a Woodchuck furnace it en-
ters into a draft
channel." Here it comes into contact with the hot fire-
bo front and is warmed before entering the firebo .
The draft channel is equipped with adjustable orifices
which provide for the 80/20 distribution of the com-
bustion air. A lever on the front of Models 2900/4000
allows for quick and easy adjustment of these orifices
to correspond to the fuel being used. As the air enters
the firebo it strikes a deflector which creates a turbu-
lence and causes the o ygen to mi thoroughly with
the gases for complete combustion.
Finally, Woodchuck Model 2900/4000 furnaces are
designed to accept a catalytic combustor. This device
will cause the small amount of unburned fuel to ignite
before entering the secondary heat e changer. The
benefits of all this are threefold:
A.) You obtain very high combustion efficiencies,
meaning you use less fuel.
B.) You reduce the amount of unburned fuel that can
collect in your chimney as creosote and hence reduce
the hazard of a chimney fire.
C.) You virtually eliminate pollution of the air we all
breathe.
Transfer efficiency refers to how effectively we trans-
fer the heat generated inside the firebo to the rooms
we want to heat. Insufficient blower capacity will result
in poor transfer allowing the unused heat to escape
up the chimney. This is why we utilize a blower with
such large air handling capacity. The large surface
area of the firebo and secondary heat e changer
provide for efficient transfer.
COMFORT
Comfort and efficiency are closely related. The more
efficient the heating system is, the more comfortable
you and your family are. Not only are the Woodchuck
furnaces efficient, they can actually increase the effi-
ciency of your home.
On a furnace with a conventional single speed
blower, the speed of the blower is a compromise
between comfort and efficiency. If the blower has a
large enough capacity to heat the home in the cold-
est weather it will cycle rapidly in milder weather so
the system air is not as warm. If this air is moved
too rapidly it can actually feel cool. Air that is mov-
ing at 3 ft. per second will feel 4° cooler than sta-
tionary air at the same temperature. If the blower
capacity is enough to operate properly in mild
weather, it will not be large enough to keep the

7
house warm in cold weather. This could cause the fur-
nace to overheat and a loss of heat up the chimney.
The result then is a compromise which is neither effi-
cient or comfortable. Woodchuck furnaces, however,
have a three speed circulation blower which can be ad-
justed via a three position rotary switch on the Comfort
Control Center. This allows the user to select the
blower speed to meet the air movement requirements
of the installation. In addition, when the weather is mild
and the furnace is operating at a lower output, the
blower can be set on low to gently move the air. Simi-
larly, when it is cold and the furnace is operated at
higher levels of heat, output can be switched to higher
speeds.
But how can all this improve the efficiency of your
home? As figure 1 illustrates, heated air rises away
from the living area and stratifies. This causes large
temperature differentials between the ceiling where
heat is lost rapidly through conduction and the floor
where children often play. By allowing for continuous
air movement, even during periods of low heat output,
this stratification is not allowed to take place. You are
more comfortable and lose less heat through your ceil-
ings as illustrated in figure 2.
This situation can be especially troublesome in
multi-level homes as illustrated in figure 3. As soon as
the blower shuts off, the air in the home begins to strat-
ify; warm air rising to the upper levels and cool air col-
lecting in the lower levels. The lower levels become
increasingly uncomfortable until the blower turns on
again. Unfortunately, the upper levels are still warm so
they become uncomfortably warm before the blower
turns off. By allowing for a steadier, more continuous
operation of the blower the entire house stays at a
more constant and comfortable level, figure 4.
ADDITIONAL COMFORT AND SAVING
Options are available for your Woodchuck furnace, and
one of these deserve special mention. The Aqua-Si-
phon is capable of pre-heating your domestic water
free of charge during the heating season for additional
saving to you.
FIGURE 1
WASTED
HEAT ZONE
82°
74°
60°
COMFORT ZONE
DISCOMFORT ZONE
THERMOSTAT
FIGURE 2
75°
THERMOSTAT
74°
73°
FIGURE 3
UNCOMFORTABLY HOT
UNCOMFORTABLY COLD
FIGURE 4

8
OPERATION
COMMON SENSE
Please read the following before firing your furnace. It is
most important that you follow these suggestions and
limitations in order to maintain your warranty and guar-
antee the long life of your furnace.
NOTE: Smoke detectors and fire e tinguishers should
always be a part of your equipment.
This furnace is an airtight unit designed to burn 6-8
hours per load of wood or coal. If the furnace is being
fired hot constantly with full flames and operating at
only 2-4 hour burn cycles, it may be over fired. Your
home heating needs may be too great for the size of
furnace you have purchased. Your furnace can be dam-
aged if fired at e tremely high temperatures.
Forced firing or abuse can be detected upon inspection
AND WILL VOID YOUR WARRANTY.
DANGER:
RISK OF FIRE OR EXPLOSION. DO NOT BURN GAR-
BAGE, GASOLINE, DRAIN OIL, OR OTHER FLAMMA-
BLE LIQUIDS. FAILURE TO HEED MAY RESULT IN
SERIOUS PERSONAL INJURY OR DEATH.
DANGER:
NEVER USE CHEMICALS OR FLUIDS SUCH AS
GASOLINE, CHARCOAL LIGHTER FLUID, DRAIN
OIL, FUEL OIL OR KEROSINE TO LIGHT A FIRE IN
YOUR WOODCHUCK. FAILURE TO HEED MAY RE-
SULT IN SERIOUS PERSONAL INJURY OR DEATH.
CAUTION:
RISK OF FIRE
DO NOT OPERATE WITH FUEL LOADING OR ASH
REMOVAL DOORS OPEN.
DO NOT STORE FUEL OR OTHER COMBUSTIBLE
MATERIAL WITHIN MARKED INSTALLATION CLEAR-
ANCES.
INSPECT AND CLEAN FLUES AND CHIMNEY REGU-
LARLY.
UNDER CERTAIN CONDITIONS OF USE, CREO-
SOTE BUILDUP MAY OCCUR RAPIDLY.
WAIT 10 SEC. ON FIRST LATCH BEFORE RE-
FUELING.
LOAD FUEL CAREFULLY OR DAMAGE MAY RE-
SULT.
! IF OU HAVE A CHIMNE FIRE !
Meyer Mfg. Corp. recommends the following actions:
1. Shut any doors and air inlet dampers and draft con-
trol. This should take no longer than a few seconds.
2. Alert everyone in the house.
3. Call the fire department.
NOTE: Emptying a large bo of bak-
ing soda will slow down the fire in
your Woodchuck.
Keeping your chimney and stove pipe clean is the best
insurance against chimney fires.
! IMPORTANT !
OPERATION PROCEDURE IN THE EVENT
OF POWER FAILURE
Your Woodchuck can operate and produce heat without
electric power. This is one of the features built into ev-
ery Woodchuck.
The following steps should be taken in the event of an
electrical power failure:
1. Locate all heating duct dampers (not smoke pipe
damper), if any, to open position.
2. Turn manual draft controls to this position.
Ash door should never be used
in power failure.
3. Remove filter bo service access
cover, allowing cooler air to move hot
air through the furnace, cooling the
plenum and the house hot air duct
system.
If power fails, to avoid product damage, close manual
draft completely. Forced draft and natural draft are preset.
In the event of a runaway fire, close all drafts. Close
smoke damper halfway.
CLOSED
MANUAL DRAFT
CLOSED
MANUAL DRAFT

9
OPERATING YOUR WOODCHUCK
FURNACE
STARTUP
Never leave ash pan in unit. Use only when cleaning
out ashes. Ash pan will block the forced draft from com-
ing in under the fire from the forced draft blower.
The first thing to check is that your main blower and
draft blower are in working order before lighting a fire.
To check the operation of the main blower, push the
manual override button on the fan/limit control for test-
ing. When finished, reset to automatic position, figure 5.
Ne t, turn the thermostat upstairs to a higher tempera-
ture then room temperature so the draft blower turns
on. The two toggle switches on the front of the comfort
control center need to be in the up or on position. With
both toggle switches in the on position and the thermo-
stat turned up to call for heat, test the draft blower.
NOTE: All models are equipped with a low limit which
will not allow the auto draft to operate when the unit is
not warm. To start the auto draft, switch the Lo limit tog-
gle switch on the comfort control center to On, figure
6.
ELECTRICAL SWITCHES
The left hand switch (Draft blower lo-limit bypass
switch) is also a start up switch. When the switch is in
the OFF-AUTO position the draft blower will run de-
pendent on the thermostat setting upstairs. If fire has
dropped to a temperature that is below the low limit
switch the draft blower will be unable to run. For starting
from a cold fire switch the Draft Blower Lo-Limit Bypass
switch to the up or On-Bypass position. This will bypass
the low limit switch and allow the draft blower to run.
Once the fire is established switch back to OFF-AUTO
position.
The right hand switch (Draft blower manual switch) is a
simple on-off switch for the draft blower. Leave this
switch in the up or ON position for normal operation.
The only reason to switch to Off would be when refuel-
ing. It is up to the customer if you choose to turn the
draft blower Off. It is not required.
FIGURE 5 WOODCHUCK CONTROLS
COMFORT
CONTROL CENTER
DOUBLE LATCH
LOADING DOOR
SHAKER
GRATE
FORCED DRAFT
BLOWER
ASH DOOR
DRAFT
CHANNEL
SELECTOR -
80/20
COMBUSTION
MODELS
2900/4000
FAN/LIMIT
HEAT EXCHANGER
CONTROL ROD
COMFORT
CONTROL CENTER
DOUBLE LATCH
LOADING DOOR
MANUAL DRAFT
(Forced Dr ft Is
Option l)
ASH DOOR
SHAKER GRATE CRANK.
SHAKER GRATES ARE OPTIONAL
MODEL 526
FAN/LIMIT
FIGURE 6 COMFORT CONTROL CENTER
CIRCULATING
BLOWER
DRAFT BLOWER
LO-LIMIT BYPASS
DRAFT BLOWER
MANUAL SWITCH

10
BURNING WOOD IN YOUR
WOODCHUCK
1. Adjust draft channel selector, figure 5, to appropriate
fuel setting on Model 2900/4000. (On model 526 with
manual draft, open it fully. Also on the Model 526 pull
the manual draft selector rod on the front of the unit
fully out. This will allow the draft to e haust out the rear
of the stack and create a hotter burn. Adjust back in
once the fire is established to maintain proper stack
temperature.) Place several pieces of crumpled paper
in the center of your Woodchuck. Criss-cross a couple
of handfuls of dry kindling wood 3/4" thickness, then
several small dry pieces of firewood. Ignite the paper
and close the door. Do not attempt to open the door im-
mediately after igniting the fire. There could be a flame
flash out.
2. It will take 5-10 minutes for the fire to establish itself.
Once you have some good red hot burning embers,
add larger pieces of wood. All chimneys and hookups
are different. After 3-4 fires, youll find out how your unit
works for the best starting.
3. After about 30-40 minutes you can adjust the draft
according to your needs. Adjust smoke pipe damper
according to your needs also.
NOTE: On airtight units, the burning time is controlled
mostly by the draft controls on the furnace, contrary to
the old type of pot belly stoves where the smoke pipe
damper controlled the burning time.
NOTE: With new steel, there is a small amount of oil or
dirt on the metal and you may smell an odor. Provide
adequate ventilating to home during the first operation.
Your new Woodchuck is capable of putting out many
BTUs, so treat it with respect. Dont fully load your fur-
nace or open all drafts fully until you have become thor-
oughly familiar with the operation of the furnace.
NOTE: A full load does not always give the best results
for your needs.
4. When loading your Woodchuck with e isting hot
coals, rake red hot embers over grates evenly. Put a
few small pieces of wood on the coals first, then
load-up.
5. If you have the automatic draft control, turn low limit
by-pass switch to On. Turn thermostat up to activate
auto draft and proceed as with manual draft. Once the
unit is warmed up you can turn the low limit by-pass
switch to OFF. This will allow the auto draft to shut off
if the unit runs out of fuel while you are gone.
CAUTION:
WAIT 10 SECONDS ON FIRST LATCH BEFORE RE-
FUELING. OPENING LOADING DOOR RAPIDLY CAN
CAUSE A FLAME TO FLASH OUT THE DOOR. THIS
OCCURS WHEN THERE IS UNBURNT FUEL AND A
LARGE AMOUNT OF GASES ON TOP OF THE FIRE-
BOX. WHEN THE DOOR IS OPEN, OXYGEN IS COM-
BINED WITH GASES AND IGNITES. USE CAUTION
WHEN OPENING LOADING DOOR.
HELPFUL HINTS
Adjust the draft to the proper setting for your home
needs. The chimney, hookups, and kind of wood will
also be a factor.
Your Woodchuck is capable of holding very large logs.
DO NOT try to add a log that is larger than you can
easily place in the furnace. You will get the best effi-
ciency when you add only the amount of wood needed
for a 6 to 8 hour burn.
In the spring and fall, the weather is mild, which will al-
low you to burn very large loads of wood for long peri-
ods of time and hence accumulate very large amounts
of creosote. KEY: Stack temperature should be
300°F-400°F for good burning. An e ternal flue temper-
ature thermometer (Woodchuck part #08-0084) is in-
cluded in the owners manual package for monitoring
stack temperature. Install the flue temperature ther-
mometer at the rear of the furnace on the smoke pipe
where it connects to the collar on the back of the
Woodchuck. 300-400 degrees should be maintained
when the Woodchuck is operating in the burn cycle with
the forced draft blower running to eliminate a creosote
build up. (If the unit has a manual draft or a natural
draft, monitor the flue temperature when the drafts are
in the open position). Depending on the weather, you
may not need a full load of wood for a good over night
burn. You will get best efficiency when you add only the
amount of wood needed until the ne t time you are
available to load.
Always try to place the logs so air can flow between
them -this will enhance combustion considerably.
ASH REMOVAL
When burning wood, run your poker over top of the
grate to be sure grate slots are clear of burnt fuel. This
should be done every morning when there is just a bed
of hot coals.

11
CAUTION
NEVER LET ASHES BUILD-UP TO GRATE LEVEL.
THIS WILL GREATLY REDUCE THE LIFE SPAN OF
YOUR GRATE.
Wood ash is useful as a fertilizer, particularly because of
its potassium content. Ashes will also decrease the acid-
ity of garden soil.
CAUTION
·
KEEP ASH PAN OUT OF UNIT DURING OPERA-
TION. ASH PAN CAN GET VERY HOT.
·
ASH CAN MUST BE PLACED ON A
NONCOMBUSTIBLE SURFACE.
·
NEVER USE ANYTHING BUT AN AIR TIGHT
METAL CONTAINER TO DUMP YOUR ASHES IN.
EVERY YEAR MANY FIRES ARE CAUSED BY
EMPTYING ASHES INTO CARDBOARD BOXES
OR PAPER BAGS.
· PROVEN FACT- SMALL RED EMBERS BURIED IN
ASH CANS STAY RED HOT FOR DAYS. ASHES
ARE A GOOD THERMAL INSULATOR AND KEEP
ENOUGH OXYGEN AWAY SO THE EMBERS DO
NOT BURN OUT.
BURNING COAL IN YOUR
WOODCHUCK
Never attempt to burn coal without a shaker grate.
Shaker grates are standard on Models 2900 and 4000
but optional on Model 526.
A barometric draft control in the smoke pipe must be
used when burning coal.
CAUTION:
UNSAFE TO LOAD COAL ABOVE TOP OF FIRE BRICK.
STARTING A COAL FIRE
Open all draft controls on your Woodchuck.
Build a fire using dry wood kindling and establish a bed
of coals. Add several small shovels of coal over the
wood coals. After the coal fire is established and spread
throughout the firebo , add larger amounts of coal to
build up the coal bed. Gently shake the grate until live
coals fall into the ash pan area. Allow your Woodchuck
to operate with drafts open for appro imately 15 minutes
or until fresh coal ignites. When the coal is properly ig-
nited, adjust the drafts accordingly. Check the fire peri-
odically to be sure it is spreading through the coal bed.
RECHARGING
Gently shake grates down. Open drafts and establish a
good flow of primary air below the grates. When re-
charging, fresh coal tends to give off large quantities of
volatile gas. This gas may accumulate and possibly ig-
nite causing a backpuff. To reduce back-puffing, open
the fire door to the first safety latch position for 15-20
seconds before opening fully. Spread fresh coal evenly
over e isting coal, leaving some hot coals e posed in
the center of the firebo . Be careful not to smother your
e isting coals. Never allow coal to build up above the
top of the firebrick. When blue flame creeps up between
the coals, drafts may be adjusted to maintain burn level.
If the coal fire dies down before recharging, a fresh sup-
ply of kindling may have to be added.
BANKING
Banking allows you to recharge in such a manner as to
retain a hot coal bed throughout the night. Appro i-
mately an hour before retiring for the night, push the
coals to the rear of the firebo with the coal tapered
down in the front. Add a new layer of coal. Always leave
some hot coals e posed in the front. This allows for
more coal to be added to the firebo .
A coal fire should not be poked or broken up as this
tends to bring ash to the surface of the coal bed where it
may fuse. If the ash fuses, clinkers will form. It may be
necessary to remove all unburned material and ash from
the firebo to remove clinkers. These should be re-
moved with gloves or tongs, and as always, put into a
metallic air-tight container.
BITUMINOUS RECHARGING
Because bituminous coal has a higher percent of sul-
phur and lower percent of fi ed carbon than anthracite,
recharging should be as follows:
Gently shake down grates, with drafts open and a good
flow of primary air entering below the grates. Push the
hot coals to the rear of the fire bo and position fresh
coal on the grate in front of the banked coal. As the
fresh coal begins to burn, wood may be added to the top
of the coal.
NOTE: Woodchuck recommends coal 1 inch to 3 inches
in diameter. Ashes may be sifted through a mesh screen
to reclaim particles of unburned coal.

12
HELPFUL HINTS
Burning coal will provide a lesson in patience. Take the
time necessary to e periment and understand the oper-
ation of your Woodchuck wood/coal furnace.
Too much draft air will cause clinkering of coal and will
waste heat up the chimney. Shut draft down to as low a
point as you can and still heat your home.
1. NEVER stand in front of loading door when opening
it. Stand to the side.
2. NEVER completely cover the live fire with fresh coal.
Always leave a generous area of burning coal at the top
of the fire and at the rear.
3. Always keep the ash pit clean.
If the fire goes out or does not hold overnight look for:
1. Poor draft.
2. Incorrect damper settings.
3. Improper firing methods for coal being used.
4. More combustion air needed.
5. Coal not sized to furnace. We recommend 1" to 3" di-
ameter pieces of coal.
6. Ashes, if allowed to accumulate in the ash pit, will not
allow the required air for combustion. Keep ash pit
clean.
ASH REMOVAL
Ash should always be put into an air-tight, metal con-
tainer.
CAUTION
·
KEEP ASH PAN OUT OF UNIT DURING OPERA-
TION. ASH PAN CAN GET VERY HOT.
·
ASH PAN MUST BE PLACED ON A
NONCOMBUSTIBLE SURFACE.
·
NEVER USE ANYTHING BUT AN AIR TIGHT
METAL CONTAINER TO DUMP YOUR ASHES IN.
EVERY YEAR MANY FIRES ARE CAUSED BY
EMPTYING ASHES INTO CARDBOARD BOXES
OR PAPER BAGS.
·
PROVEN FACT- SMALL RED EMBERS BURIED
IN ASH CANS STAY RED HOT FOR DAYS.
ASHES ARE A GOOD THERMAL INSULATOR
AND KEEP ENOUGH OXYGEN AWAY SO THE
EMBERS DO NOT BURN OUT.
Coal firing produces much more ash than wood. These
ashes must be removed often (possibly daily) in order
to avoid piling up too closely to the grates. Removal of
the coal ash will prevent warpage and damage to
grates, and allow passage of primary air to the coal
bed.
Unlike wood ash, coal ash cannot be used as fertilizer.
All coal contains small amounts of dangerous elements.
It is therefore essential that your coal ash be disposed
of in municipally designated areas.

13
MAINTENANCE
WARNING:
DISCONNECT APPLIANCE FROM ELECTRICAL
SUPPLY BEFORE SERVICING UNIT. FAILURE TO
HEED MAY RESULT IN SERIOUS PERSONAL INJURY
OR DEATH.
Keep chimney and smoke pipe clean by cleaning at least
twice during a heating season. Keeping your chimney
and stove pipes clean is the best insurance against
chimney fires.
If you clean your own chimney and stovepipe, Meyer
Manufacturing Corp. recommends purchasing the same
equipment professionals use. Brushes are available in
enough sizes and shapes to snuggly fit inside any com-
mon flue.
Replace any cracked or deteriorated firebrick. This will
prolong the life expectancy of the firebox.
Check door gasket and replace as needed.
Keep ash pit clean especially when burning coal.
Turn on your regular furnace once every month to keep
it tuned up and limber.
OPTIONAL CATALYTIC COMBUSTOR
FOR MODELS 2900/4000
NOTE: Optional catalyst not recommended for Model
2900/4000 with 6" flue adapter. Smoke spillage may oc-
cur out of door when refueling.
Even with complete combustion there is a small amount
of residue. Eventually enough will collect on the
combustor to interfere with its operation. Therefore it is
necessary to clean it periodically. To clean the
combustor simply remove from unit and run tap water
through it until no sign of residue remains. The
combustor simply slides up into the exhaust pipe stub
which protrudes down into the firebox. There are three
rods on the combustor which engage slots in the pipe
and then turn slightly to lock in place. These rods are not
symmetrical so observe their orientation when you re-
move it. Two rods are welded at 90° and they point to-
ward the rear of the firebox.
CATALYTIC ELEMENT
RODS ON RETAINER
NOTCHES IN EXHAUST
PIPE
OPTIONAL CATALYTIC
COMBUSTOR

14
PROBLEM POSSIBLE CAUSE SOLUTION
1. Main blower vibrating
when in use. Loose Allen screw on squirrel cage.
Bad motor bearings.
Weights on squirrel cage wheel moved in ship-
ment.
Tighten Allen screw, be sure squirrel
cage did not move to one side or the
other.
Return blower to your local dealer for
a replacement.
Try to adjust it yourself or return
blower for replacement.
2. Main blower continues to
run. Manual control turned on (fan/limit control). Check fan/limit control switch. Push for manual, pull for auto. If in auto
position, replace fan/limit control.
3. Main blower wont turn
on. Defective fan/limit control. Defective 3-speed blower switch.
Defective circulation blower motor.
Replace.
Replace.
Replace.
4. Draft blower staying on. Wall thermostat bad, check by turning temp. to
60° then check if draft blower is running.
Short in thermostat wire.
Home not getting heat needed to satisfy wall
thermostat.
Replace wall thermostat.
Check all wiring again.
Check on specs chart to be sure
your unit is large enough for your
home. Be sure installation is proper:
check with your local heating man.
5. Draft blower not turning
on. NOTE: Be sure switch
on blower is on.
Switch blower to the off position. Bad wall Ther-
mostat; check by turning it up to 80° and if the
draft blower does not turn on, replace thermo-
stat.
Lo limit bypass on off.
Replace thermostat.
When starting up it is necessary to
turn toggle switch on front of comfort
control center to on until unit
warms up.
6. Smell an odor from the
first fire in the furnace. New steel, small amounts of residue on the steel.
Bad weld, if smell continues for two weeks of
burning.
This will disappear in a matter of
hours.
Contact dealer immediately.
7. Not getting heat in the
home. Unit may be too small for your home; check specification chart.
Improper insulation in home allowing heat to
escape.
Improper hookup to furnace.
Ducting not sized properly for unit.
Replace with a larger unit or have
regular furnace help.
Reinsulate!
Check installation drawings and/or
consult your local heating man.
8. Flames coming out the
door when loading. E cessive amount of gases on top of the fire bo and igniting when given o ygen from open
door. NOTE: This is one of your Woodchuck
safety features built into every unit with a dou-
ble latch system.
Large amounts of unburned wood. Try to load when fire is at its lowest
point, but have enough embers left
for a good start again. NOTE: Only
you will know this time after some
e perience with your unit and instal-
lation.
TROUBLE SHOOTING

15
PROBLEM POSSIBLE CAUSE SOLUTION
9. E cessive amounts of
smoke coming out loading
door when loading.
Improper draft.
Chimney cap too close to top of chimney.
Too long of run of smoke pipe from Woodchuck
to chimney.
Measure with draft gauge-should
have .04 to .06 water column.
Relocate.
Relocate Woodchuck closer to
chimney.
10. Puffing of smoke
through draft control. Improper draft.
Down draft on chimney.
Plugged chimney.
Check draft with gauge. Should be
.04 to .06 water column.
Check for cold spots on chimney or
obstruction outside chimney. Trees
or other buildings.
Check with mirror in clean-out door
or send cleaning brush down chim-
ney. Check stovepipe connections.
11. E cessive dirt build-up
around air vent in home. Too much smoke escaping out of loading door when loading.
Bad weld in fire bo of unit.
No return air ducting.
Check problem No. 9.
Call dealer immediately.
Install return air duct.
12. Improper seal around
door. Door rope not sealing on door frame.
Loose door from shipment.
Check door rope so that all parts of
door frame are sealed, especially
corners.
Simply bend door latch in to tighten
door seal.
13. E cessive creosote
build-up.
A reminder, whatever kind of
fuel you burn, there is some
kind of residue build-up on
the furnace and chimney.
Same with wood no matter
how good the conditions.
The use of wet, frozen, or unseasoned wood.
The use of soft wood, particularly those of high resin
content such as plywood or blande with glue.
Poor natural draft or an obstruction in the stove
pipe or chimney flue.
Too long of burning times.
Inadequate amount of o ygen supplied to the
combustion chamber
Low fire or flue gas temperatures.
Uninsulated stovepipe or chimney flues, espe-
cially if construction is e terior to the house.
Air leaks in the stove pipe or chimney.
If you have to use wet wood, make
loads smaller and burn them hotter.
Avoid using if possible.
Measure draft with gauge. Should
have a minimum of .04-.06 water
columns of draft.
Smaller and hotter fires.
Adjust draft for hotter fires or in
some homes, it has been deter-
mined there was not enough in the
basement due to such an air-tight
home. We recommend 4" round
hole to the outside with a screen
on to keep varmints out.
Smaller loads of wood and hotter
fire. Stack temps. should maintain
minimum 300° to 400°.
Never use uninsulated pipe for
chimneys installed on the outside
of the house, INSULATE!
Check chimney from top to bottom.
NOTE: Creosote is a tarry liquid or
solid coming from distillation of
wood during the combustion pro-
cess. The heavier buildups, the
greater chance of a chimney fire.
NOTE: No matter how seasoned
the wood, no matter how good the
draft, you always will get a small
amount of soot buildup. Should be
cleaned before winter firing and
during mid-winters firing.

16
GENERAL REQUIREMENTS
CAUTION:
EQUIPMENT MUST BE INSTALLED BY A QUALIFIED
HEATING PERSON.
CAUTION:
ONLY CLASS A ALL-FUEL OR SOLID FUEL CHIM-
NEYS INTENDED FOR USE WITH YOUR WOOD-
CHUCK SHOULD BE USED.
FIRST AND ABOVE ALL is safety for you and your
family.
MUST USE: Class A Masonry or ULC listed, manufac-
tured Class A All Fuels Chimney.
RECOMMENDED SI E: Rectangular 8" 12" or Round
8".
DO NOT CONNECT THIS UNIT TO A CHIMNEY FLUE
SERVING ANOTHER APPLIANCE . The Woodchuck is
to be used in conjunction with a listed gas or oil fired fur-
nace or as a central furnace.
ELECTRICAL SUPPLY: 115 volts, 60HZ, 1 Phase, less
than 12 amps.
Install system with 0.2 static pressure.
Flue setting .06 W.C. Ma to .04 W.C. Min.
Wood or coal related fires are caused almost e clusively
by installation, operation or maintenance errors; but not
by unsafe equipment.
IMPORTANT: Check with your local state and federal
codes on installation at your local fire department.
PLACEMENT AND MINIMUM
CLEARANCES
CAUTION:
FURNACE MUST BE INSTALLED ON A
NON-COMBUSTIBLE FLOOR OR 3/8" THICK FIRE-
PROOF MILLBOARD OR EQUIVALENT.
Locating your unit is very important for proper draft and
most efficient heating possible. See figure 7.
INSTALLATION
FIGURE 7 LOCATING THE WOODCHUCK

17
FIGURE 8 TYPICAL CHIMNEY CHECKLIST
CLEANOUT DOOR SHOULD BE PROVIDED AND IT MUST
HAVE AN AIRTIGHT FIT IT SHOULD NOT BE LEFT OPEN
FOR ANY LENGTH OF TIME WHEN STOVE IS IN
OPERATION
FLUE SHOULD BE OF CONSTANT CROSS
SECTIONAL AREA THROUGHOUT ITS LENGTH
MIN 3 FROM TOP OF CHIMNEY TO POINT AT
WHICH IT PASSES THROUGH THE ROOF
RECOMMENDED MIN HEIGHT
APPROX 20
TOP OF CHIMNEY MUST BE AT LEAST 2 HIGHER THAN PEAK
OR HIGHEST PORTION OF ROOF WITHIN 10 HORIZONTALLY
ALSO SEE FIGURE 9
A CHIMNEY WHICH RISES WITHIN HOUSE IS BETTER
INSULATED THAN A CHIMNEY WHICH IS LOCATED OUTSIDE
THE HOUSE AND IS EXPOSED TO WEATHER
THE CHIMNEY FLUE MUST HAVE A CROSS SECTIONAL AREA
AT LEAST EQUAL TO OR LARGER THAN THAT OF THE
STOVES FLUE COLLAR; BUT NO MORE THAN TWICE THAT
AREA
THE CHIMNEY THIMBLE SHOULD BE CONSTRUCTED OF
FIRE CLAY AND SHOULD HAVE AN INSIDE DIAMETER WHICH
IS NOMINALLY EQUAL TO THE OUTSIDE DIAMETER OF THE
SMOKE PIPE TO ASSURE A REASONABLY AIR TIGHT FIT
THE THIMBLE MUST NOT EXCEED BEYOND THE FLUE
LINING
THE CAP SHOULD BE SUCH THAT IT HELPS TO PREVENT
DOWNDRAFT WHILE PROVIDING ADEQUATE EXHAUST
DRAFT

18
Your unit should be place on a non-combustible floor or
3/8" thick fireproof millboard or equivalent which e -
tends at least 8" from the sides and rear and e tends
24" from the front. Leave a minimum clearance of 36" in
front of your unit. This is for safe, easy loading and
cleaning of your unit.
Also be sure to allow enough room at the rear of the
Woodchuck for installation of the circulating blower and
filter bo .
If using your unit as an add-on, 6" minimum clearance
is required from your present furnace.
One very important step in locating your wood/coal fur-
nace is how much distance you will be from your new or
e isting chimney. The unit should be installed as close
to the chimney as possible with a minimum of elbows
(no more than 2) and no more than 6 feet horizontally
with ½" rise per foot.
CHIMNEY INSTALLATION
It is e tremely important that your Woodchuck furnace
be installed into a CLASS A CHIMNEY ONLY. These
chimneys consist of a flue-lined masonry chimney or
an approved Class A All Fuel factory built metal type.
Any other installation constitutes a fire hazard, as wood
and coal burning units have stack temperatures as
much as 300° to 1000° and may also deposit creosote
which can ignite and cause severe damage to any
chimney. MAKE SURE YOUR WOODCHUCK IS IN-
STALLED INTO A PROPER CHIMNEY.
For ma imum safety and efficiency never install the
Woodchuck furnace into the same chimney serving an-
other appliance.
A typical chimney checklist of requirements is depicted
on figure 8.
The Model 526 furnace is equipped with a 6" flue collar
having 28 sq. in. of e haust area. Models 2900 and 4000
have an 8" flue collar having 50 sq. in. of e haust area.
When connecting the furnace to the chimney maintain a
chimney flue section giving these minimum areas or
larger but not e ceeding twice this area. Some common
sizes that are acceptable are 8" round, 10" round, or
8" 12" rectangular. All Woodchuck furnaces must be in-
stalled into a chimney developing a minimum of .04 W.C.
to a ma imum of .06 W.C. inches of draft. To maintain
this range of draft, a barometric damper should be in-
stalled (see pgs. 18-20) on each unit when the draft from
the chimney is capable of e ceeding .06 W.C. inches of
draft.
Insufficient draft can contribute to smoke spillage when
the loading door is opened and to rapid creosote accu-
mulation. E cessive draft can cause high flue gas tem-
perature, loss of overall efficiency and effect the degree
of control the operator can e ert on the unit.
FIGURE 9 CHIMNEY/ROOF CLEARANCE
TYPICAL STOVE PIPE INSTALLATION
10 MIN.
2 MIN.
APPROVED CHIMNEY
6" OR 7" PIPE FOR
MODEL 526
8" PIPE FOR
MODELS
2900/4000
DAMPER
3 MIN.
SIDE VIEW FRONT VIEW
DAMPER
STOVE PIPE
APPROVED
CHIMNEY
2 MIN.

19
When using approved factory built metal chimneys, you
must have at least 2" of clearance when going through
a wall or next to a wall. A typical factory chimney instal-
lation is shown on figure 9.
INSTALLING YOUR WOODCHUCK
Most of the Woodchuck furnace is factory assembled.
The factory assembly should be located as detailed in
the PLACEMENT AND MINIMUM CLEARANCES sec-
tion and on figure 7.
Remaining assembly will consist of mounting the con-
trols, draft and circulating blowers, filter box if used, and
electrical connection. These details will be provided af-
ter stove pipe and air duct installation.
STOVE PIPE INSTALLATION
Install your Wood/Coal unit as close to the chimney as
possible with a minimum of elbows. We recommend no
more than two elbows. The maximum horizontal run
should not exceed 6 feet with a 1/2" rise per foot. The
pipe should maintain a minimum of a 1/2" rise per foot
and NEVER be installed closer than 18" from combusti-
bles. Exceeding these recommendations normally rep-
resents creosote build-up, a smoking furnace, or one
with poor draft.
When connecting stove pipe, all joints should be se-
cured with at least three #10 sheet metal screws.
NOTE: If it is absolutely necessary to make a run
greater than 6 feet (not recommended), use extra sup-
port brackets every 3 ft.
The connection to the wood furnace’s collar must also
be more than just a snug fit. Drill holes through the
Woodchuck’s collar and secure with sheet metal
screws. Mark each connection for cleaning. This will
prevent frustration when matching up your hole pattern
again.
DAMPERS IN STOVE PIPES
A manual damper may be installed at a safe convenient
place between the barometric damper and the chimney.
In the event of chimney fire, it can quickly be closed
reducing draft to the chimney. See figure 10.
INSTALLATION OF A BAROMETRIC
DRAFT
Some codes and NFPA require draft regulators in the
chimney connector of wood or coal furnaces and boil-
ers, and manufacturers recommend their use with some
stoves. There is some doubt among wood heat experts
as to whether use of barometric draft regulators is wise.
Draft regulators limit the draft-the suction pulling air into
the appliance. A pivoted, counter-balanced flap is
pulled open by the draft when the draft reaches a criti-
cal amount (figure 10). This permits air to enter the
chimney, thus preventing the draft in the appliance from
rising any higher.
Use of draft regulators with oil-fired equipment is com-
mon. One objective is to keep the oil flame from being
blown out by excessive draft. This is more an annoy-
ance than a safety problem since most oil burners have
primary safety controls which stop the fuel flow into the
burner whenever the flame goes out, and modern
flame-retention burner design makes draft regulation al-
most unnecessary for this objective.
A second objective is to limit the amount of air passing
through the system in order to maintain high heat trans-
fer efficiency. Another desirable consequence is a de-
crease in peak chimney temperatures due to the added
air entering through the regulator.
High draft does not blow out the flames but fans them in
wood and coal burning equipment. An especially hot
fire can result. Control of the fire may be difficult, partic-
ularly if the wood burner is not airtight. Energy efficien-
cies may be adversely affected, and chimney fires may
be ignited. A barometric draft regulator can alleviate
these problems by limiting the flow of combustion air
into the appliance and by adding cooling air to the hot
flue gases.
However the cooling air may result in more creosote
accumulation, and if a chimney fire does start, it will be
more intense because of the draft regulator. Large
flows of air into the regulator will fan the fire in the
chimney. Thus the net effect of barometric draft
regulators is unclear-they help in some aspects, and
hurt in others. Note, though, that if a chimney is clean
so that chimney fires are impossible, a draft regulator
does no harm, and does help limit the intensity of the
fire in the appliance, and it helps prevent the flue gases
in the chimney from getting too hot. Barometric draft
regulators are recommended by JFPA for hand fired
thermostatically controlled solid fuel furnaces.
SUGGESTED TYPE
DAMPER
AIR HOLES

20
FIGURE 10 A BAROMETRIC DRAFT REGULATOR AND ITS INTENDED EFFECT
With no dr ft in chimney, regul tor
is closed, no ir gets in.
Moder te suction in chimney pulls regul tor open
enough to m int in desired dr ft for ppli nce.
Excessive suction in chimney pulls regul tor further
open, llowing subst nti l ir into chimney connector.
MANUAL DAMPER MAY BE
INSTALLED BETWEEN BAROMETRIC
DAMPER AND CHIMNEY
AIR DUCT INSTALLATION
SPECIAL AIR FLOW CONSIDERATIONS FOR
WOOD/COAL FURNACES
With Wood/Coal furnaces, a special concern is pre-
venting wood joists and flooring close to the hot air
ducts and plenum from overheating. A fire hazard is
created by the hot air flow circulating through ducts not
designed for such high temperatures. Most Wood/Coal
furnaces produce much hotter air than oil or gas fired
units. So most clearances from the e isting ducts and
plenum are usually inadequate with a supplemental
Wood/Coal furnace installation.
When installing the air duct, follow recommended
clearances shown in figure 11.
The plenum on the Woodchuck should be 20" 23" and
no less than 18" high while maintaining a minimum of
18" clearance to the ceiling or other combustible mate-
rial. In a power outage situation, e cessive heat
buildup at the plenum top may be dangerous, so make
sure clearances are maintained. For the Model 4000
allow at least 4" from ceiling to plenum.
The ducts, fittings, grilles and registers should be sized
so that the total e ternal static pressure does not e -
ceed .02 W.C. inches while developing air velocities of
600 ft/min to 1000 ft/min at the registers. NEVER sup-
ply less than 150 sq. in. of heated air outlet area.
Cold air returns must be at least equal in size to the
heated air outlets and preferably 10% larger. Every Wood-
chuck furnace MUST be installed with a cold air return.
ADD-ON INSTALLATIONS
Before installing your Woodchuck furnace, consult
your furnace man and local state building codes to de-
termine if your furnace will accept an add-on applica-
tion. Some small furnaces and especially counter-flow
furnaces may not be used in add-on installations.
Once it has been determined that your e isting furnace
will accept an add-on installation, we recommend a
parallel installation, with direct (ducted) feed of return
air to the Wood/Coal furnace, see figure . The back
flow prevent damper assures that when either unit is
operating by itself, the hot air will flow into the home,
and not flow back through the other furnace.
Figure shows a central installation.
We do not recommend supplemental wood furnace
installations with series connection. These types of
installation are not advisable in spite of their simplicity,
see figure 14.